A Case Study on the Regulation of Static Eliminators ... · from all of the case studies to prepare a final summary report. 1.2 Scope Static eliminators are devices that contain a

VOLUME 2: APPENDIX C

RISK INFORMING THE MATERIALS AND WASTE ARENAS:

A Case Study on the Regulation of Static Eliminators

James G. Danna

U.S. Nuclear Regulatory CommissionOffice of Nuclear Material Safety and Safeguards

Washington, DC 20555 USA

December 2001

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ABSTRACT

In Commission Paper SECY-99-100, “Framework for Risk-Informed Regulation in the Office ofNuclear Material Safety and Safeguards,” dated March 31, 1999, the staff of the U.S. NuclearRegulatory Commission (NRC) proposed a framework for risk-informed regulation in thenuclear materials and waste arenas. The Commission approved the staff’s proposal anddirected the staff to develop appropriate safety goals for these arenas and to use an enhancedparticipatory process. As part of this effort, the NRC staff is conducting case studies on aspectrum of activities in the nuclear materials and waste arenas. The objectives of these casestudies are to (1) develop screening criteria for identifying regulatory applications whererisk-informed approaches would add value; (2) determine the feasibility of safety goals; (3)illustrate how the staff can apply risk information to improve regulatory processes in thematerials and waste arenas; and (4) identify the methods, data, and guidance needed toimplement a risk-informed regulatory approach.

One of the activities chosen for the case studies is the NRC’s regulation of the use ofradioactive material in static eliminators. Static eliminators are devices that contain a sealedsource of radioactive material to reduce the buildup of electric charge on equipment andmaterials that are used in consumer and commercial applications.

The NRC currently regulates the use of static eliminators under the requirements specified inTitle 10, Part 30, of the Code of Federal Regulations (10 CFR Part 30), “Rules of GeneralApplicability to Domestic Licensing of Byproduct Material,” and 10 CFR Part 31, “GeneralDomestic Licenses for Byproduct Material.” In addition, the NRC regulates manufacturing andinitial distribution of these devices under 10 CFR Part 30 and 10 CFR Part 32, “SpecificDomestic Licenses To Manufacture or Transfer Certain Items Containing Byproduct Material.”

The general risks associated with the use of static eliminators have been evaluated anddocumented in several reports. In addition, sealed sources and devices, including most staticeliminators, are registered in accordance with 10 CFR 32.210. The individual registrationcertificates provide an evaluation of risks associated with the specific devices. The availablerisk assessments and evaluations may support modifying the regulatory requirements for thesestatic eliminators.

The static eliminator case study consisted of reviewing applicable documents and interviewingNRC personnel involved with licensing byproduct material devices. The case study followed theoutline provided in the “Plan for Using Risk Information in the Materials and Waste Arenas” thatwas developed by the Risk Task Group in the NRC’s Office of Nuclear Materials Safety andSafeguards. The use and regulation of static eliminators were evaluated against questions inthree categories, including (1) screening criteria analysis/risk analysis questions, (2) safety goalanalysis questions, and (3) questions upon developing draft safety goals. These questionswere designed to meet objectives related to the effectiveness of the draft screening criteria, thecurrent and potential value of risk information, the feasibility and utility of safety goals, and theinformation needed for a risk-informed regulatory approach.

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ACKNOWLEDGMENT

The Risk Task Group would like to thank Brian Smith, Division of Industrial and Medical NuclearSafety, Office of Nuclear Material Safety and Safeguards, for his review and input to this report. We would also like to thank Michele Burgess, Binesh Tharakan, and Catherine Mattsen,Division of Industrial and Medical Nuclear Safety, Office of Nuclear Material Safety andSafeguards, for their technical guidance.

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CONTENTS

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i

ACKNOWLEDGMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii

1. INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Objectives and Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.3 Organization of the Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2. BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.1 Static Eliminators Used Under a 10 CFR 31.3 General License . . . . . . . . . . . . . . . 32.2 Static Eliminators Used Under a 10 CFR 31.5 General License . . . . . . . . . . . . . . . 42.3 Static Eliminators Used Under a Specific License . . . . . . . . . . . . . . . . . . . . . . . . . 52.4 Device Registration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52.5 Agreement States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.6 Sealed Source and Device Registry (SSDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

3. CASE STUDY APPROACH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4. RESPONSES TO DRAFT QUESTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.1 Screening Criteria Analysis/Risk Analysis Questions . . . . . . . . . . . . . . . . . . . . . . 104.2 Safety Goal Analysis Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174.3 Questions upon Developing Draft Safety Goals . . . . . . . . . . . . . . . . . . . . . . . . . . 21

5. DRAFT SCREENING CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

6. SUMMARY AND CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

7. REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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1. INTRODUCTION

In Commission Paper SECY-99-100, “Framework for Risk-Informed Regulation in the Office ofNuclear Material Safety and Safeguards,” dated March 31, 1999 [1], the staff of the U.S.Nuclear Regulatory Commission (NRC), Office of Nuclear Material Safety and Safeguards(NMSS), proposed a framework for risk-informed regulation in the nuclear materials and wastearenas. The Commission approved the staff's proposal and directed the staff to developappropriate safety goals for these arenas, and to use an enhanced participatory process thatincludes regular public meetings with all stakeholders who are involved in or affected byregulation of these arenas [2].

At the first such meeting, the NRC staff suggested that screening criteria were needed toidentify issues for which risk information would be productive. The staff further suggested thatthe development of safety goals and screening criteria would be enhanced by studying actualregulatory cases in the materials and waste arenas, to see how risk information was, or couldhave been, used. The NMSS staff adopted this suggestion and, as part of the overallrisk-informing effort, is conducting case studies of a spectrum of activities in the nuclearmaterials and waste arenas, including the transportation of radioactive materials. Theregulation of the use of static eliminators, the subject of this report, is one of these casestudies.

1.1 Objectives and Approach

The NMSS staff will consolidate the results of this case study with those from the other casestudies to further the following objectives:

(1) Produce final screening criteria for the materials and waste arenas.

(2) Illustrate how the application of risk information has improved or could improveparticular areas of the regulatory process in the materials and waste arenas.

(3) Determine the feasibility of safety goals in the particular areas studied. If feasible,develop safety goal parameters and a first draft of safety goals. Otherwise, documentthe reasons why this is infeasible.

(4) Identify methods, data, and guidance needed to implement a risk-informed regulatoryapproach.

It is not an objective of this or any other case study to reconsider the regulatory actions that theNRC took in the case being studied. The objectives are strictly those listed above.

The NMSS is conducting all of its case studies using a standardized approach. The casestudies are largely retrospective; that is, they involve regulatory and physical actions that theNRC has already taken. Each case is studied by a member of the NMSS Risk Task Group or acontractor with risk expertise. Advisors include subject matter experts from the NRC staff whohave knowledge of the particular case. The reviewers also consult with licensees and otherstakeholders having knowledge of the particular case.

The basis for each case study is the review of information from NRC and licensee sourcedocumentation, through which the staff answers a standardized list of questions that address

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aspects of the four objectives listed above. After the investigative phase of the study, theNMSS staff generates a set of preliminary conclusions on the basis of the answers to thesequestions. The staff then presents its preliminary conclusions at a public meeting in which allstakeholders are invited to participate. After incorporating information and ideas that emergefrom this meeting, the NMSS staff produces a report documenting the case study. Thisdocument is one such case study report. In addition, the NMSS staff will consolidate the resultsfrom all of the case studies to prepare a final summary report.

1.2 Scope

Static eliminators are devices that contain a sealed source of radioactive material to reduce thebuildup of electric charge on equipment and materials that are used in consumer andcommercial applications. The radiation from the radioactive source produces ions in air thatneutralize the static charges in their vicinity.

The NRC currently regulates the use, manufacturing, and initial distribution (transfer) of staticeliminators under Title 10 of the Code of Federal Regulations (10 CFR), Parts 30 through 32. Sealed sources and devices containing them may be used under a general license or a specificlicense, or may be exempt from licensing requirements. Specifically, 10 CFR Part 31 indicatesthat a static eliminator device may be used under a general license if certain conditions are met;otherwise, use of the device would be governed by a specific license. Static eliminators are notincluded in the set of exempt devices.

1.3 Organization of the Report

In addition to this introduction (Section 1), this report consists of six sections. Section 2 givesbackground information on the design, use, and regulation of static eliminators. Section 3discusses the specific approach and actions taken for this case study, including the sources ofinformation considered. Sections 4 and 5 provide the results in the form of answers to thestandardized risk questions, and the draft screening criteria that the NMSS generated. Section6 summarizes the staff’s conclusions regarding the use of risk information in the nuclearmaterials and waste arenas. Finally, Section 7 lists the references used in conducting this casestudy.

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2. BACKGROUND

As stated in Section 1.2, static eliminators are devices that contain a sealed source ofbyproduct material to reduce the buildup of electric charge on equipment and materials that areused in consumer and commercial applications. Static electric charges may develop whendifferent materials are in close contact. If the materials are nonconducting, the static charge willremain, and the presence of this static charge can lead to various problems. To combat thissituation, the radiation from the static eliminator source produces ions in air, that neutralize thestatic charges in their vicinity.

As consumer products, the use of static eliminators is generally limited to eliminating staticcharges on photographic film and lenses, as well as those that can hinder the delicate operationof precision balances. As commercial products, static eliminators are used to reduce (1) therisk of fire or explosion that might result from the buildup and discharge of static charges involatile and explosive environments (e.g., paint shops), (2) the buildup of static charges thatcan damage electronic circuits and hard drives during assembly and repair of personalcomputers, (3) the buildup of dust on surfaces to be electroplated or painted, and (4) the staticcling of processed material on sheet-fed webs and rollers (e.g., print shops).

The NRC currently regulates the use, manufacturing, and initial distribution (transfer) of staticeliminators under 10 CFR Parts 30, 31, and 32:

• 10 CFR Part 30 - Rules of General Applicability to Domestic Licensing of ByproductMaterial

• 10 CFR Part 31 - General Domestic Licenses for Byproduct Material

• 10 CFR Part 32 - Specific Domestic Licenses to Manufacture or Transfer Certain ItemsContaining Byproduct Material

In general, static eliminators may be used under a general license or a specific license. Specifically, 10 CFR Part 31 allows a static eliminator to be used under a general license ifcertain conditions are met; otherwise, use of the device would require a specific license. Themanufacturing and initial transfer of a static eliminator requires a specific license.

2.1 Static Eliminators Used Under a 10 CFR 31.3 General License

Under 10 CFR 31.3, the NRC issues a general license to transfer, receive, acquire, own,possess, and use a static elimination device containing as a sealed source no more than 500microcuries of polonium-210 (Po-210), as long as the device is manufactured, tested, andlabeled by the manufacturer under a specific license. Po-210 is an alpha emitter and a weakgamma emitter, with a half life of 138 days. These devices may be used in both consumer andcommercial applications. The general license issued under 10 CFR 31.3 to use staticeliminators is subject to the provisions of 10 CFR Part 30 that are applicable to generallicensees, including requirements and restrictions on transferring the devices, reporting to theNRC, recordkeeping, inspection, testing, and enforcement.

The specific license to manufacture a 10 CFR 31.3 generally licensed static eliminator is issuedpursuant to 10 CFR Part 30. 10 CFR Part 30 places requirements on the specifically licensedmanufacturer regarding labeling and transfer (distribution) of the devices, reporting to the NRC,

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recordkeeping, inspection, testing, and enforcement. There are approximately 30,000 of thesedevices distributed for use each year.

A safety evaluation and registration (discussed below) are not required as a prerequisite todistributing or using devices that are licensed under 10 CFR 31.3. Similarly, there are noexplicit requirements for the design, leak testing, installation, or servicing of static eliminatorsthat are generally licensed for use under the 10 CFR 31.3. However, the sealed source used inmanufacturing the devices is specifically licensed, and is subject to the safety evaluation andregistration requirements.

2.2 Static Eliminators Used Under a 10 CFR 31.5 General License

Under 10 CFR 31.5, the NRC issues a general license to transfer, acquire, receive, possess, oruse certain devices, including devices for producing an ionized atmosphere (e.g., staticelimination devices), as long as the devices are manufactured or initially transferred and labeledin accordance with the specifications of a specific license issued pursuant to 10 CFR Parts 30and 32. The general license issued under 10 CFR 31.5 is explicitly limited to commercial andindustrial firms; research, educational, and medical institutions; individuals in the conduct oftheir business; and Federal, State, or local government agencies.

10 CFR 31.5 identifies the requirements that apply to the general license holder with regard tolabeling, leak testing, recordkeeping, servicing, failure reporting, abandonment, transfer, anddisposal. The general license holder is also subject to the provisions of 10 CFR Part 30 thatare applicable to other general licensees, including requirements and restrictions ontransferring the devices, reporting to the NRC, recordkeeping, inspection, testing, andenforcement.

Manufacturing and initially transferring any 10 CFR 31.5 generally licensed static eliminatorrequires a specific license issued pursuant to 10 CFR Parts 30 and 32, specifically 10 CFR,Sections 32.51 and 32.52. 10 CFR 32.51 requires an applicant to submit an applicationcontaining information related to the design, manufacture, prototype testing, quality control,labeling, proposed leak testing, operating and safety instructions, and potential hazards of thedevice. The information provided by the manufacturer must be sufficient to provide reasonableassurance that the device meets the following criteria:

• The device can be safely operated by persons who do not have training in radiologicalprotection.

• Under ordinary conditions of handling, storage, and use of the device, the byproductmaterial contained in the device will not be released or inadvertently removed from thedevice.

• Under ordinary conditions of handling, storage, and use of the device, it is unlikely thatany person will receive in 1 year a dose that exceeds 10% of the annual limits specifiedin 10 CFR 20.1201(a) (the occupational dose limits for adults).

• Under accident conditions (such as fire or explosion) associated with handling, storageand use of the device, it is unlikely that any person would receive an external radiationdose or dose commitment that exceeds the dose to the appropriate organ as specifiedin Column IV of 10 CFR 32.24 (15 rem to the whole body, head and trunk, active blood-

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forming organs, gonads, or lens of the eye; 200 rem to the hands and forearms, feetand ankles, or localized areas of skin; 50 rem to other organs).

In addition, 10 CFR 32.51 specifies labeling, leak testing, installation, and servicingrequirements for generally licensed 10 CFR 31.5 devices, as well as other generalrequirements that apply to the specifically licensed manufacturer’s facility and operations. 10CFR 32.52 specifies material transfer reporting and recordkeeping requirements for 10 CFR31.5 devices applicable to the manufacturer.

Specific static eliminators that may be used under a general license pursuant to 10 CFR 31.5are described in Section 2.6.

2.3 Static Eliminators Used Under a Specific License

A static eliminator may also be used under a specific license issued pursuant to 10 CFR Part30. To obtain a specific license, a person must submit an application to the NRC or AgreementState (discussed below) that satisfies the requirements of 10 CFR 30.32. If a specific license isissued, the licensee is subject to specific terms and conditions of the license, as well as theother applicable requirements of 10 CFR Part 30, until the license is terminated.

Under 10 CFR 30.32(g), an application for a specific license to use a static eliminator musteither (1) identify the device by manufacturer and model number as registered with the NRC(under 10 CFR 32.210) or with an Agreement State, or (2) contain the information identified in10 CFR 32.210. The registration of static eliminators and other sealed sources and devices isdiscussed in Section 2.4.

Specific static eliminator devices requiring a specific license for use are described in Section2.6.

2.4 Device Registration

10 CFR 32.210 allows manufacturers and initial distributors of specifically licensed sealedsources and devices to submit and register the radiation safety information that is needed toperform an independent safety evaluation. Applicants for a specific license to use a particularsource or device may then reference the registration, rather than individually providing thesafety information in their applications, to satisfy the requirements of 10 CFR 30.32(g).

According to 10 CFR 32.210(c), the request for evaluation and registration must includeinformation regarding the source and device design, manufacture, prototype testing, qualitycontrol, labeling, proposed uses, and leak testing. In addition, for a device, the request mustinclude information regarding installation, service, and maintenance; operating and safetyinstructions; and the potential hazards associated with the device. The information must besufficient to provide reasonable assurance that the radiation safety properties of the source ordevice are adequate to protect health and minimize danger to life and property.

According to 10 CFR 32.210(d), the safety of a sealed source or device will be evaluated on thebasis of radiation safety criteria in accepted industry standards. If standards and criteria do notreadily apply to a particular case, the NRC will formulate reasonable standards and criteria thatwill be sufficient to ensure that the radiation safety properties of the device or sealed source areadequate to protect health and minimize danger to life and property.

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While 10 CFR 30.32(g) and 10 CFR 32.210 explicitly applies to sealed sources and devicesthat are used under a specific license, the NRC has determined that registration is necessaryfor certain exempt and generally licensed devices, including those that are used under thegeneral license pursuant to 10 CFR 31.5. Therefore, manufacturers and initial distributors ofstatic eliminators generally licensed under 10 CFR 31.5 submit a request for evaluation ofradiation safety information, and for registration of that information, according to 10 CFR32.210.

2.5 Agreement States

Agreements States have the authority to perform safety evaluations and to register byproductmaterials that are used, possessed, or distributed by persons within their borders. An applicantlocated in an Agreement State that is seeking a safety evaluation and registration of a sealedsource or device applies to the authority within that Agreement State. Agreement Statesforward copies of their registration certificates to the NRC for administrative review. Copies arethen forwarded to the NRC regions, all Agreement States, and appropriate Federal andinternational agencies. Any administrative problems or omissions are resolved directly with theAgreement State.

The NRC may determine that a sealed source or device that is registered by an AgreementState does not meet the regulations required of an NRC licensee, or may identify significantsafety concerns regarding a sealed source or device that has been evaluated by an AgreementState. In such instances, the NRC will attach a cover letter to the registration certificate,indicating why the sealed source or device is not approved for use by NRC licensees. TheNRC will raise the safety issues with the Agreement State that issued the registration certificate,as well as the vendor that manufactured of the source or device.

2.6 Sealed Source and Device Registry (SSDR)

The NRC maintains a registry of radiation safety information on sealed sources and devicesthat contain byproduct material for which the NRC or an Agreement State issued registrationcertificates. A search of the SSDR indicates that there are currently eight active registrationcertificates for static eliminator devices that are intended for use under a general license. Ofthese certificates, seven reference Po-210 as the radiation. The remaining certificatereferences krypton-85 (Kr-85) as the source.

The registered Po-210 devices include bars and disks onto which the sealed source is mountedand protected by a tamper-resistant housing and screen. These bars and disks are theninstalled in proximity to the application. The devices also include air blowers, as well ascartridges and air guns through which compressed air is blown. The activity of Po-210 in thesedevices ranges from 5 millicuries to 324 millicuries.

The 20 registered Po-210 devices employ 3 different registered sealed sources. One of thesesealed sources is Model PDM.1001, which is manufactured and distributed by AEA TechnologyQSA Inc. This foil source consists of polonium chromate dispersed in a matrix of silver. According to the registry certificate, the radioactive component is a layer approximately 1micrometer thick, sandwiched between a 0.2-millimeter silver backing and a 3-micrometer thickcover layer of palladium gold alloy. The finished foil strip is 20 millimeters wide, with the Po-210source limited to the center 10 millimeters. The foil source is cut to the length determined bythe eliminator design, the cut ends are protected with silver end caps, and the foil segment is

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electroplated 1 micrometer thick with nickel. The source concentration is 0.8 millicurie percentimeter length. The registration certificate for the device in which this foil source is usedindicates that the dose rate at the surface of the device does not exceed 0.75 millirem per hour.

A second referenced Po-210 source, Model PDM.1002, is also manufactured and distributed byAEA Technology QSA Inc., and is very similar to PDM.1001. This is also a foil source,consisting of Po-210 oxide dispersed in a gold matrix. The source layer is sandwiched betweena silver-coated copper base and a copper cover layer. The finished foil strip is 20 millimeterswide, with the Po-210 source limited to the center 11 millimeters. The source concentration is1.25 millicurie per centimeter length. The registration certificate for the devices in which this foilsource is used indicates that dose rates are less than 1 millirem per hour at 5 centimeters fromthe surface of the devices, and are less than 0.05 millirem per hour at 30 centimeters from thesurface of the devices

The third Po-210 sealed source, Model P-001, is a foil source manufactured by NRD, Inc. Thesource consists of the gold-Po-210 active layer, sandwiched between a gold overcoat andundercoat, all of which is supported by a thicker silver backing. This laminated foil is sealedwith gold through electroplating. The maximum activity reported for the source ranges between5 millicurie and 324 millicurie, depending on the length of the foil strip. The registrationcertificates for devices in which this foil source is used indicate that exposure rates are lessthan 0.2 milliroentgens per hour at the surface of the devices.

In addition to the seven active registration certificates that reference Po-210 as the radiationsource, one active registration certificate for a generally licensed static eliminator employs Kr-85 as a source. This registration covers five different devices manufactured by TSIIncorporated. For each of these devices, the krypton gas is sealed within a stainless steel tube,which is then mounted inside a stainless steel or aluminum tubular housing, ranging from 15 to50 centimeters in length and 4 to 9 centimeters in diameter. The housing is then typicallyplumbed into a flow system, and is used to eliminate static charges on solid particles in the flowstream. The activity of Kr-85 in the sealed source ranges from 1 to 10 millicuries, depending onthe device. For the 10-millicurie device, the registration certificate indicates that the dose rateon the surface of the device is 13.1 millirem per hour.

The SSDR also shows three registration certificates for static eliminators that may be used onlyunder a specific license. Two of the registration certificates are for static eliminators thatemploy americium-241 (Am-241). The third registration certificate describes a static eliminationapplication that was discontinued in the 1970s, according to the licensee.

One of the specifically licensed static eliminators that uses Am-241 is a laser transceivermanufactured and distributed through Lockheed Martin Corporation. This device is used forlaser target range and designation onboard aircraft. Contained in the device are two 4.5-microcurie Amersham Model AMM Am-241 foil sources. The AMM foil source is a gold-americium oxide mixture contained between a 0.006-millimeter thick silver backing and a 0.002millimeter face of gold or gold and palladium. The AMM foil source is also included in theSSDR.

The other specifically licensed static eliminator that uses Am-241 is the Ionotron modelmanufactured and distributed by NRD, Inc. The device consists of a foil source mounted in analuminum housing and protected by a stainless steel grid. The grid allows alpha particles to befreely emitted to ionize the ambient atmosphere. The foil source, Model A-001, is also

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manufactured by NRD, Inc., and is comprised of a gold or silver overcoat and undercoat, anactive layer of gold or silver and Am-241 oxide, and a silver or gold backing, all of which arewelded and rolled to completely seal the source. The foil unit is then gold-plated. Dependingon the application, the Am-241 content in the source may range from 0.4 microcuries per linearinch to 8350 microcuries per linear inch.

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3. CASE STUDY APPROACH

In studying this case, the NMSS staff reviewed existing and applicable documentation anddatabases, held discussions with NRC staff involved with registering and tracking staticeliminators and other sealed source devices, and conducted an interim stakeholder workshopto solicit input on preliminary findings. The workshop was held on February 9, 2001, and wasdocumented through an official transcript [3].

The NMSS staff began by reviewing 10 CFR Parts 30, 31, and 32, which apply to the licensingof byproduct material and, specifically, sealed sources and devices, as well as 10 CFR Part 20,which contains regulations applicable to existing dose limits. In addition, the NMSS staffreviewed the guidance for implementing these regulations, with respect to sealed sources anddevices, as provided in NUREG-1556, Volume 3, “Consolidated Guidance About MaterialsLicenses -- Applications for Sealed Source and Device Evaluation and Registration” [4].

The NMSS staff also queried several databases maintained by the NRC to identify records thatapply to static eliminators. Specifically, the staff searched the SSDR to retrieve, categorize,and review the registration certificates for all static eliminator sources and devices. Forcompleteness, the staff included both active and inactive registration certificates for bothgenerally and specifically licensed sources and devices. The staff also searched the NuclearMaterial Events Database (NMED) to retrieve records pertaining to events involving staticeliminators. Finally, the staff queried the General License Tracking System (GLST) forinformation related to the distribution of static eliminators.

On the basis of an Internet search and a search of internal NRC records, the NMSS staff thenretrieved and reviewed several studies related to dose and risk assessments of staticeliminators. In addition, on the basis of input received during the interim public stakeholderworkshop, the NMSS staff searched NRC records for documents related to a specific eventinvolving the recall of static eliminators manufactured by the Minnesota Mining andManufacturing Company (3M). (The recall event is discussed in Section 4.2.)

Finally, the NMSS staff consulted with other NRC staff involved with regulating byproductmaterials. This consultation included discussions with staff associated with the safetyevaluation and registration of sealed sources and devices, and others responsible formaintaining the databases mentioned above.

After reviewing all available information, the NMSS staff focused the case study on answeringthe three sets of questions in the Case Study Plan [5]. (Section 4 of this report presents theanswers to these questions.) The NMSS staff then evaluated the regulation of staticeliminators against the draft screening criteria defined in the Case Study Plan. Although thesecriteria are intended for use in determining if a particular regulatory application would beamenable to, and would benefit from, the use of risk information, in the case studies, the intentwas to evaluate the applicability and usefulness of the draft screening criteria themselves,before they are finalized. (Section 5 of this report discusses the application of the screeningcriteria in this case study.)

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4. RESPONSES TO DRAFT QUESTIONS

This section presents answers to three sets of questions identified in the Case Study Plan. TheNMSS staff developed the answers based on the information collected and reviewed throughthe case study process.

4.1 Screening Criteria Analysis/Risk Analysis Questions

(1) What risk information is currently available in this area? (Have any specific riskstudies been done?)

The existing information includes several documented, general risk-related studies thatconsider the risks associated with static eliminators. These studies express risks in terms ofradiation doses under normal and off-normal (e.g., accident, misuse) conditions.

Two early studies (listed and discussed below) considered only static eliminators that wereintended for consumer use, containing sealed sources of Po-210 with activities of no more than500 microcuries. (These would be devices that were generally licensed for use under 10 CFR31.3.) Both studies considered the Po-210 source in the form of microspheres, a form that isno longer used.

• NUREG/CR-1775, “Environmental Assessment of Consumer Products ContainingRadioactive Material” [6]

NUREG/CR-1775 assessed the impact on people and the environment, which mayresult from the use of radioactive materials in consumer products. The study focusedon the benefits and risks associated with presently distributed consumer products, andwas intended to provide a source of information for a future generic environmentalimpact statement on consumer products. Specifically, this study defined ‘consumerproducts’ as products, commodities, and materials that are available in the marketplaceas ‘off-the-shelf’ items intended for personal and household use by the general public. Hence, the study considered static eliminators that were intended for consumer use, butdid not consider products that were intended solely for industrial and medical use.

At the time the study was conducted, consumers primarily used static eliminators inphotographic and high-fidelity (phonographic) applications. Consequently, the deviceswere marketed through photographic and audio component stores. The report statesthat only one line of static eliminators containing radioactive material was manufacturedin the United States for consumer use. That line included two available sizes, onecontaining nominally 200 microcuries of Po-210 and another containing nominally 500microcuries of Po-210. The Po-210 was fixed in ceramic microspheres, which wereresin-bonded to an aluminum backing. Up to the time of the report, the maximumquantities of 200-microcurie and 500-microcurie units distributed in a year was 50,000and 20,000, respectively. NUREG/CR-1775 evaluated the radiological health impacts(committed organ doses) during normal manufacturing and distribution, use, anddisposal, as well as during accident conditions (residential and warehouse fires) andmisuse.

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• “NCRP Report No. 95, Radiation Exposure of the U.S. Population from ConsumerProducts and Miscellaneous Sources” [7]

In 1987, the National Council on Radiation Protection (NCRP) published a reportdocumenting the estimated dose equivalents received by members of the public fromconsumer products containing radioactive material. For each source category, the studyattempted to provide data on the number of products currently in use, the rate at whichthe usage was changing, and the range of typical dose equivalents received by thegeneral public. Among the various source categories, the study included staticeliminators that were used in consumer applications. The estimated dose equivalentsreported in the NCRP report were determined using the organ-dose calculations inNUREG/CR-1775. Specifically, the NCRP report assumed that 37,600 units weredistributed annually with an initial source strength of 500 microcuries. Given theseassumptions, the NCRP estimated the annual collective effective population doseequivalent and the average annual effective dose equivalent to the exposed populationduring normal use and disposal. The NCRP also estimated the effective doseequivalent to a firefighter during accident conditions (a fire in a warehouse); however,the NCRP based the estimate on the organ dose calculations reported inNUREG/CR-1775, and did not account for respiratory protection worn by firefighters.

Two more recent risk-related studies (listed and discussed below) considered static eliminatorsthat are intended for consumer use (under 10 CFR 31.3) and commercial use (under 10 CFR31.5). Both assumed Po-210 as the source, and both assumed that the sealed source was inthe form of a laminated foil, the form that is currently used.

• NUREG-1717, “Systematic Radiological Assessment of Exemptions for Source andByproduct Materials” [8]

NUREG-1717 documents an assessment of potential radiological impacts on the publicassociated with the present regulatory exemptions for source and byproduct materials. Such exemptions have generally been issued on the basis of a determination by theAtomic Energy Commission (AEC), prior to 1974, or NRC, since 1974, that thepossession, use, and transfer of the exempted materials would not constitute anunreasonable risk to public health and safety. However, the exemptions were issuedover many years, some as early as the 1940s when AEC regulations did not yet includeradiation protection standards for the public, and methods for quantitative assessmentof dose to the public had not yet been developed. Therefore, approaches used by theAEC and NRC in assessing radiological impacts on the public in support of establishingthe exemptions have varied widely. In addition, for exposures involving ingestion orinhalation of radionuclides, assessments were often based on internal dosimetry modelsand databases that, although representative of the state-of-the-art at the time, havesince been superseded and are no longer used by Federal agencies. Therefore,NUREG-1717 addressed the need to reevaluate the current exemptions for source andbyproduct materials to determine the potential radiological impacts on the public.

In addition, some items generally licensed under 10 CFR Part 31, that contain smallquantities of byproduct material, are considered potential candidates for exemption fromlicensing requirements. As part of the study, the NRC assessed of the potentialradiological impacts on the public associated with five generally licensed itemscontaining byproduct material, including static eliminators. Specifically, NUREG-1717

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evaluated individual and collective doses associated with the distribution, routine use,disposal as ordinary trash, and misuse (and accidents) of both commercial andconsumer static eliminator devices.

NUREG-1717 evaluated a source consisting of a composite foil of gold and Po-210pressure-welded onto a silver backing plate, and gold-plated to encapsulate the source.For the consumer units, the study assumed that 30,000 units are distributed annually,each with an initial polonium source of 500 microcuries. For the commercial units, thestudy assumed a source of 200 millicuries as the basis for estimating the maximumdose to an individual user, and a source of 50 millicuries and an annual distribution of10,000 units as the basis for estimating the collective radiation dose to the public. Thestudy estimated doses resulting from normal distribution, consumer and commercialuse, and disposal. The study also considered misuse and accident conditions.

During distribution, the study estimated that a single driver picking up all 40,000consumer and commercial units distributed in a single year would receive an annualeffective dose equivalent of approximately 2 millirem. Individual doses received duringnormal consumer and commercial use and disposal through landfill and incinerationwere all estimated to be much less than 1 millirem. For misuse, the study assumed thata unit was carried in an individual’s pocket for 2,000 hours during the year. For aconsumer unit, this resulted in an estimated annual effective dose equivalent of 0.2millirem to the whole body and a dose equivalent of 20 millirem to a small area of theskin. For a commercial unit, this resulted in an estimated annual effective doseequivalent of 80 millirem to the whole body and a dose equivalent of 8 rem to a smallarea of the skin. The accidents evaluated included a residential fire, a truck fire while transporting the units from the manufacturer for distribution, and a warehouse fire. Theeffective dose equivalent to an individual involved in a residential fire, without respiratoryprotection, was estimated to be 2 millirem. A firefighter (with respiratory protection) at atruck fire was estimated to receive an effective dose equivalent of 20 millirem, and anindividual (without respiratory protection) involved in the cleanup after a fire wasestimated to receive an effective dose equivalent of 200 millirem. A firefighter (withrespiratory protection) at a warehouse fire was estimated to receive an effective doseequivalent of 20 millirem, and an individual (without respiratory protection) involved inthe cleanup after a fire was estimated to receive an effective dose equivalent of 100millirem.

• NUREG/CR-6642, “Risk Analysis and Evaluation of Regulatory Options for NuclearByproduct Material Systems” [9]

NUREG/CR-6642 documents a project directed by the NRC staff to identify regulatoryoptions for byproduct material (including static eliminators) that are risk-informed (thatis, options that are formulated in light of insights obtained from risk analysis). Thespecific objectives of the project were to (1) use qualitative and, to the extent possibleand reasonable, quantitative and probabilistic tools to identify and evaluate the risksassociated with nuclear byproduct materials systems, (2) develop and apply a radiationrisk evaluation system to categorize each of those systems, and (3) develop andevaluate options for regulatory approaches and their associated costs and benefits.

The analysis grouped the full set of byproduct material licenses in a manner that wasconducive to a systematic analysis. Licensees' activities and devices were organized

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into 40 systems, each with unique features (i.e., radionuclides, source form, nature ofuse, etc.) necessary to achieve the objectives of the study. Static eliminators weregrouped into a ‘system’ with other small sealed sources (e.g., check sources, calibrationsources, scintillation detectors, Mossbauer sources, radioluminescent light sources).

Each system was described in terms of tasks, hazards, barriers, and receptors. Tasksincluded receipt and storage, installation and maintenance, use, and disposal of thedevices. Barriers (both physical and administrative) limit the doses to both the workerand the public during tasks. A barrier structure was developed according to currentregulations, guides and good practice. Development of the barrier structuredevelopment was guided by four fundamental safety functions that serve to minimize theexposure dose, including shielding from radionuclides, confinement of radionuclides, thesource strength of radionuclides, and access to radionuclides. A radiation riskassessment was performed for each of the 40 byproduct material systems, determiningboth the normal operation and accident risk for the worker and the public. Doses(consequences) and risks (consequences and associated frequencies) were quantifiedfor several event sequences that occur (or can possibly occur) for several tasksassociated with a given system. The risks were tallied to assess those that apply to eachsystem task and those that apply to the system as a whole. This risk information wasthen used to provide a risk (dose consequence and frequency) perspective forconsideration of regulatory options.

The study considered static eliminator units that are intended for both consumer andcommercial use. Po-210 source strengths for consumer units were assumed to rangefrom 200 to 500 microcuries, with 30,000 units in use. Source strengths for commercialunits were assumed to range from 10 to 50 millicuries, with 10,000 to 150,000 units inuse. On the basis of this information, the evaluation of static eliminators assumed75,000 commercial units, each with a Po-210 source strength of 50 millicuries.

The study reports risks as very low (much less than 1 millirem per year) on a per-unitbasis, under normal conditions. For a fire, with failure to follow good radiation practices,the dose to a worker is ‘higher, but well under 500 mrem.’ The maximum public doseresulting from a fire is reported as ‘less than 500 mrem.’

In addition to these four general risk-related studies, all devices that are distributed for useunder a 10 CFR 31.5 general license or a specific license undergo a device-specificindependent safety evaluation and are registered. The safety evaluation determines whetherthe device meets the applicable safety criteria, including the dose limits discussed in Section 2of this report.

(2) What is the quality of the study? (Is it of sufficient quality to supportdecisionmaking?)

NUREG/CR-1775 laid the groundwork for future studies, but should be considered outdated forthe following reasons:

• The source described (ceramic microspheres) is reportedly no longer in use.

• The study was based on consumer applications that may no longer be appropriate (e.g.,phonographic applications).

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• The study was based on dosimetry models that are no longer current (doses calculatedand reported as organ doses rather than effective dose equivalents).

• The study did not consider commercial devices or applications.

NCRP Report No. 95 was based on the information available in NUREG/CR-1775, with respectto the physical and radiological characteristics of the consumer static eliminator, itsapplications, and the estimated doses to the consumer; therefore, this study shares thelimitations and shortcomings of NUREG/CR-1775. However, the NCRP study did convert organdoses to effective dose equivalents, and it provided a relative ranking of consumer productscontaining radioactive material, on the basis of the dose to an individual and the collectivepopulation dose. This ranking provides useful insight on relative risks.

The NUREG-1717 study provides useful summary information based on evaluation of a numberof scenarios regarding the estimated doses from both consumer and commercial staticeliminators. However, the current use of static eliminators, in terms of the number and types ofdevices and the specific consumer and commercial applications, should be verified. The reportindicates that doses incurred through normal use are minimal. Significant doses are estimatedonly for accident scenarios; however, the accident scenarios are based on conservative,bounding parameter assumptions. The report does not discuss the likelihood of the accidentscenario, or the uncertainty in the results.

NUREG/CR-6642 explicitly discusses the limitations of the underlying study and the uncertaintyin the reported results. The report states that the schedule and resource limitations of the studyprecluded extensive research. Data were reportedly gathered from six sources, including (1)contractor staff and consultants, (2) the NRC staff, (3) the open literature, (4) the licensees (butonly in a limited fashion, with appropriate guidance from the staff to avoid conflict of interest andavoid imposing a data-gathering burden on licensees), (5) public comments, and (6) publiclyaccessible databases. However, it appears that data pertinent to static eliminators, regardingsource characteristics, device design, and the number of devices in use, was obtained fromNUREG-1717.

In NUREG/CR-6642, the reporting of detailed results specific to static eliminators wasprecluded by grouping the evaluation of static eliminators in a system with other small sealedsources. The report states that, in general, the risk results have large uncertainties. In mostcases, the results are reported with an uncertainty of at least an order of magnitude, withnormal risk having a smaller uncertainty and accident risks a larger uncertainty. Theuncertainties arise as a result of a lack of data in some circumstances, and a lack ofcompleteness and detail resulting from the scoping nature of the study. Whereas the largeuncertainties in the absolute values must be recognized, the relative risk values haveconsiderable usefulness for comparing one system risk to another. The robustness of therelative comparisons stems from the consistency in the risk methodology and implementation ofthat methodology from one system to another.

In developing NUREG/CR-6642, the NRC staff requested Mr. Charles B. Meinhold, President ofthe NCRP, to perform a peer review of the methodology and its application, as described in adraft version of the report. Mr. Meinhold documented the results of his peer review in a letterthat is included in Appendix B of NUREG/CR-6642. Mr. Meinhold found that “the approachtaken in [the study] exceeds admirably in developing an engineering based approach toevaluating the appropriate level of regulatory oversight based primarily on the radionuclides

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used, the quantities involved, together with all of the radiological engineering and radiologicalprotection elements used to limit exposure to these materials.”

Mr. Meinhold further stated that “the methodology and assumptions needed to calculate themyriad scenarios are given in general terms...but the effected communities (the regulators, thelicensees, the workers and members of the public) need to have access to the detailedinformation....”

None of the four general studies considers the risks associated with static eliminatorsemploying a source other than Po-210. While the source in static eliminators generally licensedunder 10 CFR 31.3 is limited to 500 microcuries of Po-210, there is no isotope or activityrestriction specified for the static eliminators that are generally licensed for use under 10 CFR31.5. In fact, static eliminators using Kr-85 are currently registered. However, the safetyevaluations performed in registering the devices do consider isotopes other than Po-210 on acase-by-case basis.

(3) What additional studies would be needed to support decisionmaking and at whatcost?

To support generally applicable regulatory decisions regarding static eliminators, the NRCneeds definitive and current information regarding their physical and radiological characteristics,and their distribution and use. This information is currently available to the NRC throughseveral registration, reporting and tracking systems. For example, since manufacturers are allspecific licensees, the NRC is able to obtain definitive descriptions of the static eliminators thatthey currently manufacture. The SSDR and the General License Tracking System provide thisinformation.

Also, the NRC needs general risk assessments of static eliminators with sources other than Po-210, such as Kr-85 and Am-241, to support regulatory decisions that are generally applicable tostatic eliminators.

(4) How is/was risk information used and considered by the NRC and licensee(s) inthis area?

As discussed, the use of static eliminators in consumer and commercial applications isspecifically licensed under 10 CFR Part 30, or generally licensed under 10 CFR 31.3 (consumerproducts) and 10 CFR 31.5 (commercial products). As such, manufacturers submit riskinformation, in terms of dose estimates, for specifically licensed static eliminators and for staticeliminators that will be used under a 10 CFR 31.5 general license. Regulatory authorities (atthe NRC or in Agreement States) perform an independent safety evaluation to ensure that thedevice will meet the regulatory dose limits, before certifying the device for use.

Regulatory authorities do not perform independent safety evaluations for devices that aregenerally licensed under 10 CFR 31.3. However, the regulations limit the isotopes and activitythat may be used in these devices, and the two recent risk studies of byproduct materials haveaddressed the general risks associated with these devices.

(5) What is the societal benefit of this regulated activity?

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As consumer products, the use of static eliminators is generally limited to eliminating staticcharges on photographic film and lenses, as well as those that can hinder the delicate operationof precision balances. As commercial products, static eliminators are used to reduce (1) therisk of fire or explosion that might result from the buildup and discharge of static charge involatile and explosive environments (e.g., paint shops), (2) the buildup of static charges thatcan damage electronic circuits and hard drives during assembly and repair of personalcomputers, (3) the buildup of dust on surfaces to be electroplated or painted, (4) the static clingof processed material on sheet-fed webs and rollers (e.g., print shops), and (5) static charge onfilters used in industrial-hygiene monitoring applications.

The nature of the devices permits their use in industrial settings and configurations that may notbe feasible for other non-radioactive devices, for physical or safety reasons (e.g., in thepresence of combustibles). Thus, the use of static eliminators results in a direct economic andsafety benefit to society.

(6) What is the public perception/acceptance of risk in this area?

On the basis of the information considered during this case study, public perception andacceptance of risk associated with the use of static eliminators in consumer and commercialapplications may be considered to be comparable to the perception and acceptance associatedwith the use of exempt devices. Approximately 30,000 of the generally licensed devices areused by the general public each year, and all of the generally licensed devices distributed eachyear are used by individuals with no required radiological training.

During the public workshop in February 2001, a few stakeholders expressed concern withreducing the regulation of static eliminators. However, no definitive information regarding thepublic perception or acceptance of risk is available.

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4.2 Safety Goal Analysis Questions

(1) What is the basis for the current regulations in this area (e.g., legislativerequirements, international compatibility, historical events, public confidence,undetermined, etc.)?

The use of static eliminators in consumer and commercial applications is permitted undergeneral licenses that are issued pursuant to 10 CFR 31.3 and 31.5. This authorization datesback to before June 26, 1965, when the regulations pertaining to the licensing of byproductmaterial were recodified (30 FR 8189). The use of static eliminators may also be authorizedunder the more rigorous requirements of a specific license, pursuant to 10 CFR Part 30.

Use of static eliminators under a general license reflects the risks associated with the devicerelative to other uses of byproduct materials and the widespread use of the devices inconsumer and commercial applications. The general license requirement allows control,traceability, and performance verification of the devices that would not be possible if the deviceswere exempt from licensing requirements.

Conversely, use under a specific license would require each user of a static eliminatorcontaining byproduct material to prepare and submit a license application to the NRC orAgreement State. Such applications would require review and approval, and the regulatoryauthority would issue a specific license to the applicant. Given that there are tens of thousandsof static eliminators in use, this would require thousands of license applications and reviews. This would likely be an impossible task and, more importantly, it would draw resources awayfrom higher-risk activities without yielding a commensurate reduction in risk.

(2) Are there any explicit safety goals or implicit safety goals embedded in theregulations, statements of consideration, or other documents (an example wouldbe the acceptance of a regulatory exemption based in part on a risk analysis andthe outcome)?

There are both explicit and implicit safety goals embedded in the regulations, guidancedocuments, and sealed source and device registration certificates. These goals are bothquantitative and qualitative.

Static eliminators containing a sealed source of no more than 500 microcuries of Po-210 maybe used in both consumer and commercial applications under a 10 CFR 31.3 general license. The device must be manufactured, tested, and labeled by the manufacturer in accordance withthe specifications of a specific license. This implies that an acceptable level of safety isprovided by the quantity of the particular radionuclide, together with the physical properties ofthe sealed source and device. The general license issued under 10 CFR 31.3 to use staticeliminators is subject to the provisions of 10 CFR Part 30 that are applicable to generallicensees, including requirements and restrictions on transferring the devices, reporting to theNRC, recordkeeping, inspection, testing, and enforcement.

Static eliminators may also be used in the commercial sector pursuant to 10 CFR 31.5. Theregulations and the individual sealed source and device registration certificates for thesedevices identify several quantitative safety goals. According to 10 CFR 32.51, an applicant fora specific license to manufacture a 10 CFR 31.5 device must submit information that issufficient to provide reasonable assurance that, under ordinary conditions of handling, storage,

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and use of the device, the byproduct material contained in the device will not be released orinadvertently removed from the device (i.e., zero release). This is quantified in the regulationsthrough the specific leak test threshold of 0.005 microcuries of removable contamination. Also,the manufacturer must demonstrate that, under ordinary conditions, it is unlikely that anyperson will receive in 1 year a dose that exceeds 10% of the annual occupational dose limits foradults specified in 10 CFR 20.1201(a).

Additionally, 10 CFR 32.51 requires that, under accident conditions (such as fire or explosion)associated with handling, storage, and use of the device, it is unlikely that any person wouldreceive an external radiation dose or dose commitment in excess of the dose to the appropriateorgan as specified in Column IV of 10 CFR 32.24 (15 rem to the whole body, head and trunk,active blood-forming organs, gonads, or lens of the eye; 200 rem to the hands and forearms,feet and ankles, or localized areas of skin; 50 rem to other organs). A review of the registrationcertificates for these devices indicates that the reviewer’s safety evaluation of each device isbased on the applicant’s ability to demonstrate conformance to these requirements.

Several qualitative safety goals may also be identified. Review of the registration certificatesindicates that the devices should be designed so that the user of the device will not come intodirect contact with the sealed source. Also, the registration certificates indicate that the devicesshould only be used in environments that will not lead to degradation of the containmentcapability of the sealed source. Additionally, distributors and users of 10 CFR 31.5 devices arerequired to demonstrate control of the devices, through reporting to the regulatory authorities.

(3) What was the basis for the development of the strategic goals, performancegoals, measures, and metrics? How are they relevant/applicable to the area beingstudied, and how do they relate/compare with the regulatory requirements? Howwould they relate to safety goals in this area?

The strategic goal for the NRC’s nuclear materials safety arena is to “prevent radiation-relateddeaths and illnesses, promote the common defense and security, and protect the environmentin the use of source, byproduct, and special nuclear material.” This strategic goal is supportedby four performance goals, and subordinate strategies, measures, and metrics. These arepresented in the agency’s Strategic Plan [10].

The regulation of byproduct material in static eliminators relates to all four of the performancegoals. The devices are regulated to adequately maintain the safety of workers and the public,to protect the environment, and to ensure public confidence in this regulation. This is balancedby the goals to make the agency’s activities and decisions effective, efficient, and realistic, andto reduce unnecessary regulatory burden on stakeholders.

(4) Are there any safety goals, limits, or other criteria implied by decisions orevaluations that have been made that are relevant to this area?

As previously discussed in this report, applicants that intend to distribute a static eliminatorunder the general license provisions of 10 CFR 31.5 are required to submit safety-relatedinformation to regulatory authorities, who then conduct a safety evaluation to determine whetherthe device will meet the applicable regulatory requirements during its use. The decision toissue a registration certificate documents the determination on the part of the regulatoryauthority that the device meets the applicable safety requirements.

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In 1988, the NRC issued a series of orders to a particular manufacturer and distributor of staticeliminators, Minnesota Mining and Manufacturing Company (3M). The orders required 3M tosuspend distribution and to recall static eliminators employing Po-210 in the form of“microspheres” as the source. These devices were being used in commercial manufacturingapplications. Evidence indicated that the sealed sources were failing and the microsphereswere being released from the devices, thereby resulting in contamination of the manufacturingenvironment, workers and other individuals in the manufacturing environment, and possibly themanufactured products.

A review of the agency’s records indicates that the decision to issue the recall orders wasbased on the evidence of release of the radioactive material from the sealed source device, andthe subsequent contamination of the immediate environment, workers and others in theenvironment, and the products being manufactured. While the risks associated with thecontamination are not evident, the chronic failure of the devices and the resulting contaminationwere sufficient to support the recall orders. A safety goal of zero release from a sealed sourcemay, therefore, be inferred from this decision.

(5) If safety goals were to be developed in this area, would tools/data be available formeasurement?

At least four potential safety goals may be identified:

• doses should be only a small fraction of the limits currently existing in the regulations,applicable to normal and accident conditions

• no direct contact with the sealed source contained within the device

• zero release from the sealed source (i.e., complete containment of the byproductmaterial)

• control and accountability for the byproduct material contained within the devices

The existing regulatory requirements provide the tools and data necessary to evaluate theextent to which these safety goals are met. Rigorous tracking of the devices and therequirements for returning the devices to the manufacture would facilitate measurement againstthe second, third, and fourth goals. Upon receipt, manufacturers would be able to verify thatthe device is intact and that the sealed source within the device has not been contacted. Current requirements for leak testing upon return would allow verification of completecontainment of the source. Given that there has been no direct contact with the source and norelease from the sealed source, compliance with the first goal may be inferred. The fourth goalwould allow different accounting requirements for different isotopes, based on their respectivehalf-lives. Accounting requirements may be less stringent for isotopes with relatively short half-lives, such as Po-210, given that the devices would be self-extinguishing after a relatively shorttime.

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(6) Who are/were the populations at risk?

The populations at risk under normal use are those in close contact with the devices. Theseare the consumers using devices licensed under 10 CFR 31.3, and the workers in proximity tothe devices used in commercial applications under 10 CFR 31.5. Also at risk are the individualswho transport the devices between the manufacturers and the users.

Populations at risk under accident conditions are varied. These include the individualsresponding to an accident, such as firefighters and other emergency response personnel. Inthe case of misuse, such as tampering with the device, individuals at risk would include thosedoing the tampering, as well as those coming into contact with the device after tampering.

Loss of control of the devices places other populations at risk. For lost devices or devices thatare disposed of improperly, this would include members of the general public who find or comein contact with the devices.

(7) What are/were, and what could be/have been, the various consequences to thepopulations at risk?

The consequences to the populations at risk under normal use are generally low. Consequences from the sealed source are limited to external exposure, which is minimal, asdemonstrated in the general risk studies and safety evaluations discussed above.

Under accident or off-normal conditions, the consequences may be more significant. For staticeliminators using Po-210 as the source, these consequences are estimated in the general riskstudies discussed above (NUREG-1717 and NUREG/CR-6642), and are dominated by theinhalation and ingestion of the air-borne alpha-emitting radionuclides. Consequencesassociated with accident and off-normal conditions for static eliminators using other isotopicsources have not been evaluated.

(8) What parameters should be considered for the safety goals (e.g., workers vs.public, individual vs. societal, accidents vs. normal operations, acute vs. latentfatality or serious injury, environmental and property damage)?

Several possible safety goals are discussed above. In general, safety goals for generallylicensed static eliminators should not differentiate between workers and the public, since theregulations state that the use of the device should not presume any special training inradiological protection. The goals should also reflect protection of the individual through thedesign of the sealed source and device, and protection of the population through control andaccountability. Safety goals should address accident conditions, as well as normal conditions,since the available risk information indicates that accident conditions can pose significant risks. Safety goals should also reflect protection of the environment and property, in terms ofcontainment of the isotope within the sealed source. Safety goals for specifically licensed staticeliminators may differentiate between workers, who may have radiation protection training, andthe general public, who would not.

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(9) On the basis of the answers to the questions above, would it be feasible todevelop safety goals in this regulatory area?

Development of safety goals for the use of static eliminators is feasible, as evidenced by thepreceding discussions.

(10) What methods, data results, safety goals, or regulatory requirements would benecessary to make it possible to risk-inform similar cases?

This case study focused on static eliminators containing byproduct material, used under ageneral license or specific license. However, much of the discussion is applicable to otherdevices that use byproduct material in the form of sealed sources. Requirements regardingdesign features, performance testing (i.e., leak testing), and control and accountability aregenerally applicable.

The risk insights gained through this case study may be applicable to sealed sources anddevices used under a general license and employing similar isotopes and quantities. Similarcases would require isotope-specific assessments, because of the relatively short half-life ofPo-210. Otherwise, the discussion of safety goal development should be generally applicableto other generally licensed devices.

4.3 Questions upon Developing Draft Safety Goals

The Commission established two qualitative safety goals applicable to the reactor safetystrategic arena (51 FR 30028):

• Individual members of the public should be provided a level of protection from theconsequences of nuclear power plant operation such that individuals bear no significantadditional risk to life and health.

• Societal risks to life and health from nuclear power plant operation should becomparable to or less than the risks of generating electricity by viable competingtechnologies and should not be a significant addition to other societal risks.

Subsequently, the Commission directed the staff to develop safety goals for the nuclearmaterials and waste strategic arenas analogous to the reactor safety goals (SECY-99-100).

As stated, one of the objectives of the case studies is to determine the feasibility of safety goalsand, if feasible, develop safety goal parameters and a first draft of safety goals. The previousset of ten questions, and the following set of five questions, address this objective. Inanswering the previous set of questions (specifically, question 2 of the Safety Goal AnalysisQuestions), implicit and explicit safety goals were identified. These goals were embedded inregulations and other documents specific to static eliminators and other sealed sources. However, they seem to fall into a general set of qualitative safety goals which have broadermaterials and waste applications:

• Nuclear materials use and disposal should not pose a significant additional risk to lifeand health of individual members of the public, and to workers associated with theseactivities.

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• Societal risks to life and health from nuclear materials use and disposal should not be asignificant addition to other societal risks.

• Nuclear materials use and disposal should not result in environmental or propertydamage in excess of other means of achieving a similar end objective that is deemedbeneficial to society.

Thus, for the purpose of answering the following set of five questions, these preliminary draftqualitative safety goals were considered. These preliminary draft safety goals are generallyanalogous to the reactor safety goals, but have been developed to include worker safety, andprotection of the environment. It is stressed that these draft safety goals are preliminary andwill likely be modified in the near future, but are presented to focus attention and prepareanswers to the set of case study questions that follows.

(1) Are the current regulations sufficient in that they reflect the objectives of the draftgoals? Would major changes be required?

The draft safety goals address risk to individuals, societal risks, and damage to the environmentor property. The existing regulations sufficiently reflect the objective of the individual-risk safetygoal for normal conditions, but not for accident conditions. Under normal conditions, theregulations limit the consequence (dose) to an individual from a sealed source or device to afraction of the allowable public dose limit specified in 10 CFR Part 20. This would not likelypose significant additional risks to the life and health of individual members of the public or toworkers associated with the use and disposal of these devices. The regulatory dose limit underaccident conditions is much greater (15 rem to the whole body, head and trunk, activeblood-forming organs, gonads, or lens of the eye; 200 rem to the hands and forearms, feet andankles, or localized areas of skin; 50 rem to other organs.) The regulation, however, does notaddress the likelihood of the accident occurring.

The existing regulations do not sufficiently reflect the objective of the societal-risk safety goalfor either normal or accident conditions. The regulations do not address the size of thepopulation that may be exposed to risk.

The environmental and property protection safety goal is reflected in the regulations. Theregulations specifically address control and accountability of the devices, and zero release ofradioactive material from the device.

(2) Would the regulations need to be tightened?

To address individual risk under accident conditions, the regulations should discuss thelikelihood of accident scenarios as well as the consequences. To address the societal risksafety goal, the regulations could be expanded to address risk from the use and disposal of thedevices integrated over the populations incurring the risk.

(3) Are the regulations overly conservative and/or too prescriptive with respect to thegoals?

The dose limits and leakage limits of the regulations do not seem overly conservative. Specificrequirements pertaining to control and disposal of devices may be overly conservative andprescriptive, depending on the half-life of the particular radionuclide used in the device.

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(4) If these were the safety goals, what decisions would be made?

Decisions would not necessarily be very different from those currently being made. As statedabove, the regulations do not seem overly conservative. The exception may be staticeliminators using polonium-210 as the source, where regulations may currently be overlyprescriptive. In general, the goals may be helpful to the staff in making decisions that areconsistent and commensurate with the risk the device presents.

(5) Would these goals be acceptable to the public?

At the Stakeholders Meeting held on October 25, 2001, there was general agreement by thestakeholders that NRC should proceed with development of safety goals in the nuclearmaterials and waste arenas. The goals presented in this section are cast in a frameworksimilar to the one that has been in existence for over 15 years for nuclear power plants.

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5. DRAFT SCREENING CRITERIA

One of the stated objectives of the case studies is to develop screening criteria for identifyingregulatory applications where risk-informed approaches would add value. Draft screeningcriteria were identified in the case study plan, and the information obtained through theindividual case studies is used to evaluate the adequacy and applicability of the draft screeningcriteria. The following discusses the application of the draft screening criteria to the regulationof static eliminators.

(1) Would a risk-informed regulatory approach help to resolve a question withrespect to maintaining or improving the activity’s safety?

A risk-informed regulatory approach would help to resolve questions with respect to maintainingor improving the safety of static eliminators. Use of static eliminators is currently regulatedunder one of two types of general license or under a specific license. Quantifying the risksassociated with the various types of static eliminators would allow a review of licensingrequirements to identify where the use of static eliminators may be over- or under-regulated,relative to the potential risks (e.g., whether certain generally licensed static eliminators may bemoved to exempt status). It also allows applicants, licensees, regulators, and otherstakeholders to make regulatory decisions on a case-by-case basis, while ensuring that safetyis maintained. With respect to specific events involving static eliminators and other devices,risk information will allow a response to the events in a manner that is commensurate withmaintaining safety.

(2) Could a risk-informed regulatory approach improve the efficiency or effectiveness of the NRC’s regulatory process?

A risk-informed regulatory approach in the nuclear materials and waste arenas would improvethe efficiency and effectiveness of the NRC’s regulatory process by providing a greater degreeof consistency in the way static eliminators are licensed, relative to other generally licenseddevices and activities and exemptions for byproduct and source materials. For example,classifying some static eliminators as exempt, consistent with the associated risk, may modestlyincrease the resources available to regulate generally licensed devices and applications thatpose more significant risks to workers, the public, and the environment. (Currently, the NRCexpends very little resources on the regulation of static eliminators.) Alternatively, taking abroader perspective across sealed sources of byproduct material, modifying the requirementsimposed on devices that use short-lived isotopes, such as Po-210, based on risk information,may more significantly increase efficiency and effectiveness through resource allocation.

(3) Could a risk-informed regulatory approach reduce unnecessary regulatory burdenfor the applicant or licensee?

A risk-informed regulatory approach would reduce unnecessary regulatory burden on bothapplicants and licensees. Manufacturers of static eliminators would be relieved of some of therequirements specified in 10 CFR Parts 30 and 32, to the extent that the regulations apply tomanufacturers and distributors of exempt devices. Commercial users of static eliminatorswould be relieved of the testing, reporting and disposal requirements specified in 10 CFR 31.5. While consumer users of static eliminators are generally licensed under 10 CFR 31.3, thisregulation does not impose any specific requirements on the licensee. None the less, theburden on consumer users would also be reduced in that they would no longer be directed by

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manufacturers (through labeling and instructions accompanying the devices) to return theexpired devices to the manufacturer.

(4) Would a risk-informed approach help to effectively communicate a regulatorydecision or situation?

A risk-informed regulatory approach would help to effectively communicate regulatory decisionsor situations. Any changes to the regulatory requirements imposed on general licensees wouldbe proposed for comment before they were implemented. Using risk information to support anyregulatory changes would allow the agency to communicate to stakeholders and otherinterested parties the impact of the change with respect to safety. Similarly, risk informationwould allow the agency to communicate the basis for its response to events involving byproductmaterials.

(5) Do information (data) and analytical models exist that are of sufficient quality, orcould they be reasonably developed to support risk-informing a regulatoryactivity?

The information and analytical models needed to support risk-informed regulation in the nuclearmaterials and waste arenas either exists or could reasonably be developed. The available riskinformation, its limitations and applicability, and additional data needs are discussed in Section4 of this case study report.

(6) Can startup and implementation of a risk-informed approach be realized at areasonable cost to the NRC, applicant or licensee, and/or the public, and providea net benefit? The net benefit will be considered to apply to the public, theapplicant or licensee, and the NRC. The benefit to be considered can beimprovement of public health and safety, improved protection of the environment,improved regulatory efficiency and effectiveness, improved communication to thepublic, and/or reduced regulatory burden (which translates to reduced cost to thepublic.)

This case study did not yield a clear answer to this question. The NUREG/CR-6642 study,discussed in Section 4, provides a foundation for risk-informing the byproduct materialsprogram. Additionally, specific risk assessments may be required to supplement this study. Itis possible that any regulatory changes that would affect static eliminators, based on riskinformation, would involve changing distribution and reporting requirements for manufacturesand licensees. This would require rulemaking. Also, such a change would likely involvethousands of licensees. However, without identifying a specific regulatory change, the totalcost cannot be determined.

(7) Do other factors exist (e.g., legislative, judicial, adverse stakeholder reaction)which would preclude changing the regulatory approach in an area, and therefore,limit the utility of implementing a risk-informed approach?

No known factors specifically related to static eliminators would preclude or limit the usefulnessof a risk-informed regulatory approach in the nuclear materials and waste arenas. Manydifferent types of devices containing byproduct material are currently used under general andspecific licenses, and some devices are exempt from licensing altogether. There are presently

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numerous devices within each category, demonstrating that the use of byproduct materialsunder significantly different licensing frameworks is possible and accepted. A few stakeholdersindicated during the stakeholder workshop, however, that any changes that result in additionalexempt devices may raise concerns with the public.

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6. SUMMARY AND CONCLUSIONS

This section organizes the staff’s conclusions to address the four objectives of the case studies,as numbered below.

1. What did the case study say about the effectiveness of the screening criteria?

The first four draft screening criteria are based on the four performance goals for the nuclearmaterial safety arena, identified in the NRC’s Strategic Plan. These four draft screening criteriaare adequate to demonstrate that increasing the use of risk information in the regulation ofstatic eliminators would support the agency’s strategic and performance goals for the nuclearmaterials safety arena.

The remaining three screening criteria adequately support the assessment of feasibility. Oneaddresses technical feasibility, the next evaluates whether there would be a net benefit, and thelast addresses any other significant obstacles or considerations that may preclude regulatoryactions. The case study indicates that risk-informing the regulation of static eliminators wouldbe technically feasible; however; it is not clear whether there would be a significant net benefit,in terms of increased efficiency and effectiveness in the NRC’s regulatory process, or reducedburden on the stakeholders (licensed manufacturers and users).

2. What insights did the case study provide about the current and potential value ofusing risk-information? What process improvements could be made to facilitateapplying risk information in similar situations?

This case study showed that risk information may have the potential to reduce regulatoryburden and improve the staff’s efficiency in making decisions, without increasing risk. Theextent to which there may be a net benefit, however, is undetermined.

The case study indicated that, while there are two generic risk studies addressing staticeliminators, the risks associated with individual models of static eliminators are evaluated on acase-by-case basis through the sealed source and device registration process. There may bepotential for increasing the efficiency of the regulatory process by making more generalregulatory decisions based on isotope and activity, or sealed source and device design. Also,the regulation under 10 CFR 31.3 may be better integrated with the static eliminator regulationunder 10 CFR 31.5, and some devices may be suitable for exempt status.

Risk insights may be used to make the regulation of static eliminators more consistent withother generally licensed, specifically licensed, and exempt devices, from a risk perspective,thus increasing regulatory effectiveness and efficiency and reducing unnecessary regulatoryburden, while maintaining health and safety.

3. What did the case study say about the feasibility and utility of safety goals? Whatwere the implicit/explicit safety goals or elements?

The case study indicates that it would be feasible to develop safety goals for the regulation ofsealed sources and devices, and specifically static eliminators. The case study identifiedseveral explicit and implicit quantitative and qualitative safety goals in the existing regulatoryframework. These included the dose limits for normal and accident conditions, the requirementfor complete containment of byproduct material within the sealed source, the prevention of

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direct contact with the sealed source through the design of the device, and control andaccountability of the byproduct material during distribution, use, and disposal.

4. What insights did the case study provide on the information, tools, methods, andguidance needed for a risk-informed regulatory approach in this specific casestudy area and (if possible) in other similar regulatory areas?

A review of the existing studies and databases indicated that a significant amount of riskinformation exists for static eliminators and other sealed sources and devices. For staticeliminators, the generic risk studies focus only on generally licensed devices that use Po-210. The generic studies do not address generally licensed or specifically licensed static eliminatorsthat use other isotopes, such as Kr-85 or Am-241. However, all the devices currently registeredfor use have undergone an independent safety evaluation.

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7. REFERENCES

[1] U.S. Nuclear Regulatory Commission, “Framework for Risk-Informed Regulation in theOffice of Nuclear Material Safety and Safeguards,” SECY-99-100, March 31, 1999.

[2] U.S. Nuclear Regulatory Commission, memorandum from A. Vietti-Cook to W.T.Travers, U.S. Nuclear Regulatory Commission, “Staff Requirements -- SECY-99-100 --Framework for Risk-Informed Regulation in the Office of Nuclear Material Safety andSafeguards,” June 28, 1999.

[3] U. S. Nuclear Regulatory Commission, "Official Transcript of Proceedings, PublicMeeting on February 9, 2001," February 2001.

[4] U.S. Nuclear Regulatory Commission, “Consolidated Guidance About MaterialsLicenses: Applications for Sealed Source and Device Evaluation and Registration,”NUREG-1556, Volume 3, July 1998.

[5] U.S. Nuclear Regulatory Commission, “Plan for Using Risk Information in the Materialsand Waste Arena,” ADAMS Accession Number ML010040111, October 2000.

[6] U.S. Nuclear Regulatory Commission, “Environmental Assessment of ConsumerProducts Containing Radioactive Material,” NUREG/CR-1775, October 1980.

[7] National Council on Radiation Protection and Measurements, “Radiation Exposure ofthe U.S. Population from Consumer Products and Miscellaneous Sources,” NCRPReport No. 95, December 1987.

[8] U.S. Nuclear Regulatory Commission, “Systematic Radiological Assessment ofExemptions for Source and Byproduct Materials,” Draft NUREG-1717, December 1999.

[9] U.S. Nuclear Regulatory Commission, “Risk Analysis and Evaluation of RegulatoryOptions for Nuclear Byproduct Material Systems,” NUREG/CR-6642, February 2000.

[10] U.S. Nuclear Regulatory Commission, “Strategic Plan: Fiscal Year 2000 -- Fiscal Year2005,” NUREG-1614, Volume 2, October 2000.